Field of the Invention
This invention relates to a tone generation device, method and distribution medium. More specifically, the invention relates to a tone generation device, method, and distribution medium, whereby the quantity of data handled in the various processing stages, such as reading data for generating tones from memory, processing it, and storing it into memory again, is such that the delay time from when there is a request for expression of prescribed tone until it is actually expressed causes no problems, and it is handled collectively in a quantity such that the bus can be used effectively.
Advances in semiconductor technology have made it possible to have on a single chip an arithmetic processing device (for example, a central processing unit (CPU) or digital signal processor (DSP) and a main memory device (for example, dynamic random access memory (DRAM) or static RAM (SRAM)). Data is passed between them via a bus.
In a conventional tone generation device, sound source processing such as pitch conversion or envelope processing is done by these arithmetic processing devices with a period Ts (time of sampling period) corresponding to a sampling frequency of 44.1 kHz or 48.0 kHz, that is every 1/44,100 second or 1/48,000 second.
For example, as shown in FIG. 1, data for generating tones that is stored in a memory, etc. is read by the arithmetic processing device in a quantity corresponding to 1 Ts. Then the arithmetic processing device performs pitch conversion or other sound source processing on this 1-Ts data that has been read and temporarily writes it into memory for subsequent processing (processing by a later-stage arithmetic processing device). A tone is generated by repeating this operation as many times as necessary.